[mirror_ubuntu-artful-kernel.git] / fs / nfs / callback.c

/*
 * linux/fs/nfs/callback.c
 *
 * Copyright (C) 2004 Trond Myklebust
 *
 * NFSv4 callback handling
 */

#include <linux/completion.h>
#include <linux/ip.h>
#include <linux/module.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/nfs_fs.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/sunrpc/bc_xprt.h>

#include <net/inet_sock.h>

#include "nfs4_fs.h"
#include "callback.h"
#include "internal.h"
#include "netns.h"

#define NFSDBG_FACILITY NFSDBG_CALLBACK

struct nfs_callback_data {
	unsigned int users;
	struct svc_serv *serv;
};

static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
static DEFINE_MUTEX(nfs_callback_mutex);
static struct svc_program nfs4_callback_program;

static int nfs4_callback_up_net(struct svc_serv *serv, struct net *net)
{
	int ret;
	struct nfs_net *nn = net_generic(net, nfs_net_id);

	ret = svc_create_xprt(serv, "tcp", net, PF_INET,
				nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	if (ret <= 0)
		goto out_err;
	nn->nfs_callback_tcpport = ret;
	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
			nn->nfs_callback_tcpport, PF_INET, net);

	ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
				nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	if (ret > 0) {
		nn->nfs_callback_tcpport6 = ret;
		dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
				nn->nfs_callback_tcpport6, PF_INET6, net);
	} else if (ret != -EAFNOSUPPORT)
		goto out_err;
	return 0;

out_err:
	return (ret) ? ret : -ENOMEM;
}

/*
 * This is the NFSv4 callback kernel thread.
 */
static int
nfs4_callback_svc(void *vrqstp)
{
	int err;
	struct svc_rqst *rqstp = vrqstp;

	set_freezable();

	while (!kthread_should_stop()) {
		/*
		 * Listen for a request on the socket
		 */
		err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
		if (err == -EAGAIN || err == -EINTR)
			continue;
		svc_process(rqstp);
	}
	return 0;
}

#if defined(CONFIG_NFS_V4_1)
/*
 * The callback service for NFSv4.1 callbacks
 */
static int
nfs41_callback_svc(void *vrqstp)
{
	struct svc_rqst *rqstp = vrqstp;
	struct svc_serv *serv = rqstp->rq_server;
	struct rpc_rqst *req;
	int error;
	DEFINE_WAIT(wq);

	set_freezable();

	while (!kthread_should_stop()) {
		if (try_to_freeze())
			continue;

		prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
		spin_lock_bh(&serv->sv_cb_lock);
		if (!list_empty(&serv->sv_cb_list)) {
			req = list_first_entry(&serv->sv_cb_list,
					struct rpc_rqst, rq_bc_list);
			list_del(&req->rq_bc_list);
			spin_unlock_bh(&serv->sv_cb_lock);
			finish_wait(&serv->sv_cb_waitq, &wq);
			dprintk("Invoking bc_svc_process()\n");
			error = bc_svc_process(serv, req, rqstp);
			dprintk("bc_svc_process() returned w/ error code= %d\n",
				error);
		} else {
			spin_unlock_bh(&serv->sv_cb_lock);
			schedule();
			finish_wait(&serv->sv_cb_waitq, &wq);
		}
		flush_signals(current);
	}
	return 0;
}

static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
		struct svc_serv *serv)
{
	if (minorversion)
		/*
		 * Save the svc_serv in the transport so that it can
		 * be referenced when the session backchannel is initialized
		 */
		xprt->bc_serv = serv;
}
#else
static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
		struct svc_serv *serv)
{
}
#endif /* CONFIG_NFS_V4_1 */

static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
				  struct svc_serv *serv)
{
	int nrservs = nfs_callback_nr_threads;
	int ret;

	nfs_callback_bc_serv(minorversion, xprt, serv);

	if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)
		nrservs = NFS4_MIN_NR_CALLBACK_THREADS;

	if (serv->sv_nrthreads-1 == nrservs)
		return 0;

	ret = serv->sv_ops->svo_setup(serv, NULL, nrservs);
	if (ret) {
		serv->sv_ops->svo_setup(serv, NULL, 0);
		return ret;
	}
	dprintk("nfs_callback_up: service started\n");
	return 0;
}

static void nfs_callback_down_net(u32 minorversion, struct svc_serv *serv, struct net *net)
{
	struct nfs_net *nn = net_generic(net, nfs_net_id);

	if (--nn->cb_users[minorversion])
		return;

	dprintk("NFS: destroy per-net callback data; net=%p\n", net);
	svc_shutdown_net(serv, net);
}

static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
			       struct net *net, struct rpc_xprt *xprt)
{
	struct nfs_net *nn = net_generic(net, nfs_net_id);
	int ret;

	if (nn->cb_users[minorversion]++)
		return 0;

	dprintk("NFS: create per-net callback data; net=%p\n", net);

	ret = svc_bind(serv, net);
	if (ret < 0) {
		printk(KERN_WARNING "NFS: bind callback service failed\n");
		goto err_bind;
	}

	ret = -EPROTONOSUPPORT;
	if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
		ret = nfs4_callback_up_net(serv, net);
	else if (xprt->ops->bc_up)
		ret = xprt->ops->bc_up(serv, net);

	if (ret < 0) {
		printk(KERN_ERR "NFS: callback service start failed\n");
		goto err_socks;
	}
	return 0;

err_socks:
	svc_rpcb_cleanup(serv, net);
err_bind:
	nn->cb_users[minorversion]--;
	dprintk("NFS: Couldn't create callback socket: err = %d; "
			"net = %p\n", ret, net);
	return ret;
}

static struct svc_serv_ops nfs40_cb_sv_ops = {
	.svo_function		= nfs4_callback_svc,
	.svo_enqueue_xprt	= svc_xprt_do_enqueue,
	.svo_setup		= svc_set_num_threads,
	.svo_module		= THIS_MODULE,
};
#if defined(CONFIG_NFS_V4_1)
static struct svc_serv_ops nfs41_cb_sv_ops = {
	.svo_function		= nfs41_callback_svc,
	.svo_enqueue_xprt	= svc_xprt_do_enqueue,
	.svo_setup		= svc_set_num_threads,
	.svo_module		= THIS_MODULE,
};

struct svc_serv_ops *nfs4_cb_sv_ops[] = {
	[0] = &nfs40_cb_sv_ops,
	[1] = &nfs41_cb_sv_ops,
};
#else
struct svc_serv_ops *nfs4_cb_sv_ops[] = {
	[0] = &nfs40_cb_sv_ops,
	[1] = NULL,
};
#endif

static struct svc_serv *nfs_callback_create_svc(int minorversion)
{
	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	struct svc_serv *serv;
	struct svc_serv_ops *sv_ops;

	/*
	 * Check whether we're already up and running.
	 */
	if (cb_info->serv) {
		/*
		 * Note: increase service usage, because later in case of error
		 * svc_destroy() will be called.
		 */
		svc_get(cb_info->serv);
		return cb_info->serv;
	}

	switch (minorversion) {
	case 0:
		sv_ops = nfs4_cb_sv_ops[0];
		break;
	default:
		sv_ops = nfs4_cb_sv_ops[1];
	}

	if (sv_ops == NULL)
		return ERR_PTR(-ENOTSUPP);

	/*
	 * Sanity check: if there's no task,
	 * we should be the first user ...
	 */
	if (cb_info->users)
		printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
			cb_info->users);

	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops);
	if (!serv) {
		printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
		return ERR_PTR(-ENOMEM);
	}
	cb_info->serv = serv;
	/* As there is only one thread we need to over-ride the
	 * default maximum of 80 connections
	 */
	serv->sv_maxconn = 1024;
	dprintk("nfs_callback_create_svc: service created\n");
	return serv;
}

/*
 * Bring up the callback thread if it is not already up.
 */
int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
{
	struct svc_serv *serv;
	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	int ret;
	struct net *net = xprt->xprt_net;

	mutex_lock(&nfs_callback_mutex);

	serv = nfs_callback_create_svc(minorversion);
	if (IS_ERR(serv)) {
		ret = PTR_ERR(serv);
		goto err_create;
	}

	ret = nfs_callback_up_net(minorversion, serv, net, xprt);
	if (ret < 0)
		goto err_net;

	ret = nfs_callback_start_svc(minorversion, xprt, serv);
	if (ret < 0)
		goto err_start;

	cb_info->users++;
	/*
	 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
	 * svc_prepare_thread increments that. So we need to call svc_destroy
	 * on both success and failure so that the refcount is 1 when the
	 * thread exits.
	 */
err_net:
	if (!cb_info->users)
		cb_info->serv = NULL;
	svc_destroy(serv);
err_create:
	mutex_unlock(&nfs_callback_mutex);
	return ret;

err_start:
	nfs_callback_down_net(minorversion, serv, net);
	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
	goto err_net;
}

/*
 * Kill the callback thread if it's no longer being used.
 */
void nfs_callback_down(int minorversion, struct net *net)
{
	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	struct svc_serv *serv;

	mutex_lock(&nfs_callback_mutex);
	serv = cb_info->serv;
	nfs_callback_down_net(minorversion, serv, net);
	cb_info->users--;
	if (cb_info->users == 0) {
		svc_get(serv);
		serv->sv_ops->svo_setup(serv, NULL, 0);
		svc_destroy(serv);
		dprintk("nfs_callback_down: service destroyed\n");
		cb_info->serv = NULL;
	}
	mutex_unlock(&nfs_callback_mutex);
}

/* Boolean check of RPC_AUTH_GSS principal */
int
check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
{
	char *p = rqstp->rq_cred.cr_principal;

	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
		return 1;

	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
	if (clp->cl_minorversion != 0)
		return 0;
	/*
	 * It might just be a normal user principal, in which case
	 * userspace won't bother to tell us the name at all.
	 */
	if (p == NULL)
		return 0;

	/*
	 * Did we get the acceptor from userland during the SETCLIENID
	 * negotiation?
	 */
	if (clp->cl_acceptor)
		return !strcmp(p, clp->cl_acceptor);

	/*
	 * Otherwise try to verify it using the cl_hostname. Note that this
	 * doesn't work if a non-canonical hostname was used in the devname.
	 */

	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */

	if (memcmp(p, "nfs@", 4) != 0)
		return 0;
	p += 4;
	if (strcmp(p, clp->cl_hostname) != 0)
		return 0;
	return 1;
}

/*
 * pg_authenticate method for nfsv4 callback threads.
 *
 * The authflavor has been negotiated, so an incorrect flavor is a server
 * bug. Deny packets with incorrect authflavor.
 *
 * All other checking done after NFS decoding where the nfs_client can be
 * found in nfs4_callback_compound
 */
static int nfs_callback_authenticate(struct svc_rqst *rqstp)
{
	switch (rqstp->rq_authop->flavour) {
	case RPC_AUTH_NULL:
		if (rqstp->rq_proc != CB_NULL)
			return SVC_DENIED;
		break;
	case RPC_AUTH_GSS:
		/* No RPC_AUTH_GSS support yet in NFSv4.1 */
		 if (svc_is_backchannel(rqstp))
			return SVC_DENIED;
	}
	return SVC_OK;
}

/*
 * Define NFS4 callback program
 */
static struct svc_version *nfs4_callback_version[] = {
	[1] = &nfs4_callback_version1,
	[4] = &nfs4_callback_version4,
};

static struct svc_stat nfs4_callback_stats;

static struct svc_program nfs4_callback_program = {
	.pg_prog = NFS4_CALLBACK,			/* RPC service number */
	.pg_nvers = ARRAY_SIZE(nfs4_callback_version),	/* Number of entries */
	.pg_vers = nfs4_callback_version,		/* version table */
	.pg_name = "NFSv4 callback",			/* service name */
	.pg_class = "nfs",				/* authentication class */
	.pg_stats = &nfs4_callback_stats,
	.pg_authenticate = nfs_callback_authenticate,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/nfs/callback.c
	3	*
	4	* Copyright (C) 2004 Trond Myklebust
	5	*
	6	* NFSv4 callback handling
	7	*/
	8
1da177e4 LT	9	#include <linux/completion.h>
	10	#include <linux/ip.h>
	11	#include <linux/module.h>
1da177e4 LT	12	#include <linux/sunrpc/svc.h>
	13	#include <linux/sunrpc/svcsock.h>
	14	#include <linux/nfs_fs.h>
758201e2	15	#include <linux/errno.h>
353ab6e9	16	#include <linux/mutex.h>
83144186	17	#include <linux/freezer.h>
a277e33c	18	#include <linux/kthread.h>
945b34a7	19	#include <linux/sunrpc/svcauth_gss.h>
a43cde94	20	#include <linux/sunrpc/bc_xprt.h>
14c85021 ACM	21
	22	#include <net/inet_sock.h>
	23
4ce79717	24	#include "nfs4_fs.h"
1da177e4	25	#include "callback.h"
24c8dbbb	26	#include "internal.h"
bbe0a3aa	27	#include "netns.h"
1da177e4 LT	28
	29	#define NFSDBG_FACILITY NFSDBG_CALLBACK
	30
	31	struct nfs_callback_data {
	32	unsigned int users;
a43cde94	33	struct svc_serv *serv;
1da177e4 LT	34	};
1da177e4 LT	35
e82dc22d	36	static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
353ab6e9	37	static DEFINE_MUTEX(nfs_callback_mutex);
1da177e4 LT	38	static struct svc_program nfs4_callback_program;
1da177e4 LT	39
c946556b SK	40	static int nfs4_callback_up_net(struct svc_serv serv, struct net net)
	41	{
	42	int ret;
bbe0a3aa	43	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	44
	45	ret = svc_create_xprt(serv, "tcp", net, PF_INET,
	46	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	47	if (ret <= 0)
	48	goto out_err;
bbe0a3aa	49	nn->nfs_callback_tcpport = ret;
c946556b	50	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
bbe0a3aa	51	nn->nfs_callback_tcpport, PF_INET, net);
c946556b SK	52
	53	ret = svc_create_xprt(serv, "tcp", net, PF_INET6,
	54	nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
	55	if (ret > 0) {
29dcc16a	56	nn->nfs_callback_tcpport6 = ret;
c946556b	57	dprintk("NFS: Callback listener port = %u (af %u, net %p)\n",
29dcc16a	58	nn->nfs_callback_tcpport6, PF_INET6, net);
c946556b SK	59	} else if (ret != -EAFNOSUPPORT)
	60	goto out_err;
	61	return 0;
	62
	63	out_err:
	64	return (ret) ? ret : -ENOMEM;
	65	}
	66
1da177e4	67	/*
e82dc22d	68	* This is the NFSv4 callback kernel thread.
1da177e4	69	*/
a277e33c	70	static int
71468513	71	nfs4_callback_svc(void *vrqstp)
1da177e4	72	{
5b444cc9	73	int err;
a277e33c	74	struct svc_rqst *rqstp = vrqstp;
1da177e4	75
83144186	76	set_freezable();
1da177e4	77
a277e33c	78	while (!kthread_should_stop()) {
1da177e4 LT	79	/*
	80	* Listen for a request on the socket
	81	*/
6fb2b47f	82	err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
5b444cc9	83	if (err == -EAGAIN \|\| err == -EINTR)
1da177e4	84	continue;
6fb2b47f	85	svc_process(rqstp);
1da177e4	86	}
a277e33c	87	return 0;
1da177e4 LT	88	}
1da177e4 LT	89
a43cde94 RL	90	#if defined(CONFIG_NFS_V4_1)
	91	/*
	92	* The callback service for NFSv4.1 callbacks
	93	*/
	94	static int
	95	nfs41_callback_svc(void *vrqstp)
	96	{
	97	struct svc_rqst *rqstp = vrqstp;
	98	struct svc_serv *serv = rqstp->rq_server;
	99	struct rpc_rqst *req;
	100	int error;
	101	DEFINE_WAIT(wq);
	102
	103	set_freezable();
	104
a43cde94	105	while (!kthread_should_stop()) {
25d280aa JL	106	if (try_to_freeze())
	107	continue;
	108
5d05e54a	109	prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
a43cde94 RL	110	spin_lock_bh(&serv->sv_cb_lock);
	111	if (!list_empty(&serv->sv_cb_list)) {
	112	req = list_first_entry(&serv->sv_cb_list,
	113	struct rpc_rqst, rq_bc_list);
	114	list_del(&req->rq_bc_list);
	115	spin_unlock_bh(&serv->sv_cb_lock);
6ffa30d3	116	finish_wait(&serv->sv_cb_waitq, &wq);
a43cde94 RL	117	dprintk("Invoking bc_svc_process()\n");
	118	error = bc_svc_process(serv, req, rqstp);
	119	dprintk("bc_svc_process() returned w/ error code= %d\n",
	120	error);
	121	} else {
	122	spin_unlock_bh(&serv->sv_cb_lock);
5d05e54a	123	schedule();
6ffa30d3	124	finish_wait(&serv->sv_cb_waitq, &wq);
a43cde94	125	}
5d05e54a	126	flush_signals(current);
a43cde94	127	}
a43cde94 RL	128	return 0;
	129	}
	130
a43cde94	131	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	132	struct svc_serv *serv)
a43cde94 RL	133	{
a43cde94 RL	134	if (minorversion)
691c457a SK	135	/*
	136	* Save the svc_serv in the transport so that it can
	137	* be referenced when the session backchannel is initialized
	138	*/
	139	xprt->bc_serv = serv;
a43cde94 RL	140	}
a43cde94 RL	141	#else
a43cde94	142	static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
691c457a	143	struct svc_serv *serv)
a43cde94 RL	144	{
	145	}
	146	#endif /* CONFIG_NFS_V4_1 */
	147
8e246144 SK	148	static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
	149	struct svc_serv *serv)
	150	{
5405fc44	151	int nrservs = nfs_callback_nr_threads;
8e246144	152	int ret;
8e246144 SK	153
	154	nfs_callback_bc_serv(minorversion, xprt, serv);
	155
5405fc44 TM	156	if (nrservs < NFS4_MIN_NR_CALLBACK_THREADS)
	157	nrservs = NFS4_MIN_NR_CALLBACK_THREADS;
	158
bb6aeba7	159	if (serv->sv_nrthreads-1 == nrservs)
23c20ecd SK	160	return 0;
23c20ecd SK	161
bb6aeba7 TM	162	ret = serv->sv_ops->svo_setup(serv, NULL, nrservs);
	163	if (ret) {
	164	serv->sv_ops->svo_setup(serv, NULL, 0);
e9b7e917	165	return ret;
8e246144 SK	166	}
	167	dprintk("nfs_callback_up: service started\n");
	168	return 0;
	169	}
	170
b3d19c51 SK	171	static void nfs_callback_down_net(u32 minorversion, struct svc_serv serv, struct net net)
	172	{
	173	struct nfs_net *nn = net_generic(net, nfs_net_id);
	174
	175	if (--nn->cb_users[minorversion])
	176	return;
	177
	178	dprintk("NFS: destroy per-net callback data; net=%p\n", net);
	179	svc_shutdown_net(serv, net);
	180	}
	181
76566773 CL	182	static int nfs_callback_up_net(int minorversion, struct svc_serv *serv,
76566773 CL	183	struct net net, struct rpc_xprt xprt)
c946556b	184	{
b3d19c51	185	struct nfs_net *nn = net_generic(net, nfs_net_id);
c946556b SK	186	int ret;
c946556b SK	187
b3d19c51 SK	188	if (nn->cb_users[minorversion]++)
	189	return 0;
	190
c946556b SK	191	dprintk("NFS: create per-net callback data; net=%p\n", net);
	192
	193	ret = svc_bind(serv, net);
	194	if (ret < 0) {
	195	printk(KERN_WARNING "NFS: bind callback service failed\n");
	196	goto err_bind;
	197	}
	198
76566773	199	ret = -EPROTONOSUPPORT;
d55b352b	200	if (!IS_ENABLED(CONFIG_NFS_V4_1) \|\| minorversion == 0)
76566773 CL	201	ret = nfs4_callback_up_net(serv, net);
	202	else if (xprt->ops->bc_up)
	203	ret = xprt->ops->bc_up(serv, net);
c946556b SK	204
	205	if (ret < 0) {
	206	printk(KERN_ERR "NFS: callback service start failed\n");
	207	goto err_socks;
	208	}
	209	return 0;
	210
	211	err_socks:
	212	svc_rpcb_cleanup(serv, net);
	213	err_bind:
98b0f80c	214	nn->cb_users[minorversion]--;
23c20ecd SK	215	dprintk("NFS: Couldn't create callback socket: err = %d; "
23c20ecd SK	216	"net = %p\n", ret, net);
c946556b SK	217	return ret;
	218	}
	219
f4b52bb0 TM	220	static struct svc_serv_ops nfs40_cb_sv_ops = {
f4b52bb0 TM	221	.svo_function = nfs4_callback_svc,
b9e13cdf	222	.svo_enqueue_xprt = svc_xprt_do_enqueue,
bb6aeba7	223	.svo_setup = svc_set_num_threads,
f4b52bb0 TM	224	.svo_module = THIS_MODULE,
	225	};
	226	#if defined(CONFIG_NFS_V4_1)
	227	static struct svc_serv_ops nfs41_cb_sv_ops = {
	228	.svo_function = nfs41_callback_svc,
	229	.svo_enqueue_xprt = svc_xprt_do_enqueue,
bb6aeba7	230	.svo_setup = svc_set_num_threads,
f4b52bb0	231	.svo_module = THIS_MODULE,
ea126e74 JL	232	};
ea126e74 JL	233
f4b52bb0 TM	234	struct svc_serv_ops *nfs4_cb_sv_ops[] = {
	235	[0] = &nfs40_cb_sv_ops,
	236	[1] = &nfs41_cb_sv_ops,
	237	};
	238	#else
	239	struct svc_serv_ops *nfs4_cb_sv_ops[] = {
	240	[0] = &nfs40_cb_sv_ops,
	241	[1] = NULL,
	242	};
	243	#endif
	244
dd018428 SK	245	static struct svc_serv *nfs_callback_create_svc(int minorversion)
	246	{
	247	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
	248	struct svc_serv *serv;
f4b52bb0	249	struct svc_serv_ops *sv_ops;
dd018428 SK	250
	251	/*
	252	* Check whether we're already up and running.
	253	*/
3b01c11e	254	if (cb_info->serv) {
dd018428 SK	255	/*
	256	* Note: increase service usage, because later in case of error
	257	* svc_destroy() will be called.
	258	*/
	259	svc_get(cb_info->serv);
	260	return cb_info->serv;
	261	}
	262
f4b52bb0 TM	263	switch (minorversion) {
	264	case 0:
	265	sv_ops = nfs4_cb_sv_ops[0];
	266	break;
	267	default:
	268	sv_ops = nfs4_cb_sv_ops[1];
	269	}
	270
	271	if (sv_ops == NULL)
	272	return ERR_PTR(-ENOTSUPP);
	273
dd018428 SK	274	/*
	275	* Sanity check: if there's no task,
	276	* we should be the first user ...
	277	*/
	278	if (cb_info->users)
	279	printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
	280	cb_info->users);
	281
f4b52bb0	282	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, sv_ops);
dd018428 SK	283	if (!serv) {
	284	printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
	285	return ERR_PTR(-ENOMEM);
	286	}
3b01c11e	287	cb_info->serv = serv;
dd018428 SK	288	/* As there is only one thread we need to over-ride the
	289	* default maximum of 80 connections
	290	*/
	291	serv->sv_maxconn = 1024;
	292	dprintk("nfs_callback_create_svc: service created\n");
	293	return serv;
	294	}
	295
71468513 BH	296	/*
	297	* Bring up the callback thread if it is not already up.
	298	*/
	299	int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
	300	{
dd018428	301	struct svc_serv *serv;
e82dc22d	302	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
23c20ecd	303	int ret;
c946556b	304	struct net *net = xprt->xprt_net;
71468513 BH	305
71468513 BH	306	mutex_lock(&nfs_callback_mutex);
dd018428 SK	307
	308	serv = nfs_callback_create_svc(minorversion);
	309	if (IS_ERR(serv)) {
	310	ret = PTR_ERR(serv);
	311	goto err_create;
	312	}
	313
76566773	314	ret = nfs_callback_up_net(minorversion, serv, net, xprt);
c946556b SK	315	if (ret < 0)
c946556b SK	316	goto err_net;
9793f7c8	317
8e246144 SK	318	ret = nfs_callback_start_svc(minorversion, xprt, serv);
	319	if (ret < 0)
	320	goto err_start;
a277e33c	321
23c20ecd	322	cb_info->users++;
8e60029f JL	323	/*
8e60029f JL	324	* svc_create creates the svc_serv with sv_nrthreads == 1, and then
a277e33c	325	* svc_prepare_thread increments that. So we need to call svc_destroy
8e60029f JL	326	* on both success and failure so that the refcount is 1 when the
	327	* thread exits.
	328	*/
23c20ecd	329	err_net:
3b01c11e TM	330	if (!cb_info->users)
3b01c11e TM	331	cb_info->serv = NULL;
dd018428 SK	332	svc_destroy(serv);
dd018428 SK	333	err_create:
353ab6e9	334	mutex_unlock(&nfs_callback_mutex);
1da177e4	335	return ret;
8e246144 SK	336
8e246144 SK	337	err_start:
b3d19c51	338	nfs_callback_down_net(minorversion, serv, net);
23c20ecd SK	339	dprintk("NFS: Couldn't create server thread; err = %d\n", ret);
23c20ecd SK	340	goto err_net;
1da177e4 LT	341	}
	342
	343	/*
5afc597c	344	* Kill the callback thread if it's no longer being used.
1da177e4	345	*/
c8ceb412	346	void nfs_callback_down(int minorversion, struct net *net)
1da177e4	347	{
e82dc22d	348	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
bb6aeba7	349	struct svc_serv *serv;
e82dc22d	350
353ab6e9	351	mutex_lock(&nfs_callback_mutex);
bb6aeba7 TM	352	serv = cb_info->serv;
bb6aeba7 TM	353	nfs_callback_down_net(minorversion, serv, net);
e82dc22d	354	cb_info->users--;
3b01c11e	355	if (cb_info->users == 0) {
bb6aeba7 TM	356	svc_get(serv);
	357	serv->sv_ops->svo_setup(serv, NULL, 0);
	358	svc_destroy(serv);
1dc42e04	359	dprintk("nfs_callback_down: service destroyed\n");
e82dc22d	360	cb_info->serv = NULL;
5afc597c	361	}
353ab6e9	362	mutex_unlock(&nfs_callback_mutex);
1da177e4 LT	363	}
1da177e4 LT	364
778be232 AA	365	/* Boolean check of RPC_AUTH_GSS principal */
	366	int
	367	check_gss_callback_principal(struct nfs_client clp, struct svc_rqst rqstp)
945b34a7	368	{
03a4e1f6	369	char *p = rqstp->rq_cred.cr_principal;
945b34a7	370
778be232 AA	371	if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
	372	return 1;
	373
ece0de63 AA	374	/* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
ece0de63 AA	375	if (clp->cl_minorversion != 0)
778be232	376	return 0;
945b34a7 OK	377	/*
	378	* It might just be a normal user principal, in which case
	379	* userspace won't bother to tell us the name at all.
	380	*/
	381	if (p == NULL)
778be232	382	return 0;
945b34a7	383
f11b2a1c JL	384	/*
	385	* Did we get the acceptor from userland during the SETCLIENID
	386	* negotiation?
	387	*/
	388	if (clp->cl_acceptor)
	389	return !strcmp(p, clp->cl_acceptor);
	390
	391	/*
	392	* Otherwise try to verify it using the cl_hostname. Note that this
	393	* doesn't work if a non-canonical hostname was used in the devname.
	394	*/
	395
945b34a7 OK	396	/* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
	397
	398	if (memcmp(p, "nfs@", 4) != 0)
778be232	399	return 0;
945b34a7	400	p += 4;
4e0038b6	401	if (strcmp(p, clp->cl_hostname) != 0)
778be232 AA	402	return 0;
778be232 AA	403	return 1;
945b34a7 OK	404	}
945b34a7 OK	405
778be232 AA	406	/*
	407	* pg_authenticate method for nfsv4 callback threads.
	408	*
	409	* The authflavor has been negotiated, so an incorrect flavor is a server
6f02dc88	410	* bug. Deny packets with incorrect authflavor.
778be232 AA	411	*
	412	* All other checking done after NFS decoding where the nfs_client can be
	413	* found in nfs4_callback_compound
	414	*/
1da177e4 LT	415	static int nfs_callback_authenticate(struct svc_rqst *rqstp)
1da177e4 LT	416	{
1da177e4	417	switch (rqstp->rq_authop->flavour) {
778be232 AA	418	case RPC_AUTH_NULL:
778be232 AA	419	if (rqstp->rq_proc != CB_NULL)
6f02dc88	420	return SVC_DENIED;
778be232 AA	421	break;
	422	case RPC_AUTH_GSS:
	423	/* No RPC_AUTH_GSS support yet in NFSv4.1 */
	424	if (svc_is_backchannel(rqstp))
6f02dc88	425	return SVC_DENIED;
1da177e4	426	}
778be232	427	return SVC_OK;
1da177e4 LT	428	}
	429
	430	/*
	431	* Define NFS4 callback program
	432	*/
1da177e4 LT	433	static struct svc_version *nfs4_callback_version[] = {
1da177e4 LT	434	[1] = &nfs4_callback_version1,
07bccc2d	435	[4] = &nfs4_callback_version4,
1da177e4 LT	436	};
	437
	438	static struct svc_stat nfs4_callback_stats;
	439
	440	static struct svc_program nfs4_callback_program = {
	441	.pg_prog = NFS4_CALLBACK, /* RPC service number */
	442	.pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
	443	.pg_vers = nfs4_callback_version, /* version table */
	444	.pg_name = "NFSv4 callback", /* service name */
	445	.pg_class = "nfs", /* authentication class */
	446	.pg_stats = &nfs4_callback_stats,
	447	.pg_authenticate = nfs_callback_authenticate,
	448	};